Broken belt detector and safety device



April '18; 1933. A. A. BIANCHI BROKEN BELT DETECTOR AND SAFETY DEVICE Filed Oct. 5, 1927 3 Sheets-Sheet l April 18, 1933. A. A. BIANCHI BROKEN BELT DETECTOR AND SAFETY DEVICE 3 Sheets-Sheet 2 Filed Oct. 5, 1927 Ap 1933- A. A. BIANCHI 1,904,351

BROKEN BELT DETECTOR AND SAFETY DEVICE Filed Oct. 1927 3 Sheets-Sheet 5 mig may

H lhave found that a clock can be installed Patented Apr.'18, 1933 UNIT D STATES.

ALFRED A. j BIANCHI, orwoncnsrnn, mssncnusnrrrs BROKEN BELT nn'rnc'ron AND sArn'rY iinvrcn- Application niea octoter'ii, 1927. Serial no. 224,154..

The invention relates to indicating devices and stopmotions to causejpowerto be shut ofi upon the breakage of a belt or other driving means. The invention i has particular 5 utility in connection with macaroni-drying machinery of the type disclosed in the patent toSicignano, No. 1,174,627, granted March 71916. a In such a machine,aplurality of fans are driven by a motor in order that the macaroni may be 'dried'. Although not so shown in the patent to Sicignano referred to, it has been the practice-to duplicate the arrangement 'shown by him; that is. to say, the fans are located in the middle of the drying room, and macaroni is hung on bothsides thereof, and at. intervals the fans are reversedlby reversing the direction of rotation of the driving motor). In reversing the motor care had to be taken to start the motor again in the reverse direction of travelvery slowly, as

otherwise the fiat belts provided wouldjunipl off the pulleys. Therefore, manual labor was necessary to reverse the motors.

to reverse the motors at the proper time if the belts can be kept from running off, or 1f some means can be provided to stop the particular motor in question, or to indicate that a belt.

' has broken or run ofi. (It will be und e'rstood that a macaronifactory provides. a great number of drying rooms.) To prevent the. belts from running off I have employed grooved pulleys and a type of V-belt made out of a great number of smallpiecesof leather link-edtogether.

T'heuse of such belts, or the equivalent, eliminates the possibility of the belts jumping Oh when the motors are reversed, but obviously there is still the possibility ofbreakage of the belts. When a flat leather belt broke, the particular drying room in question was put out. of operation, which was bad enough as the macaroni was apt to spoil, but when one of the V-belts breaks, there is an additional detriment; whereas the fiat belts,

when they broke, would simply drop off the pulleys, the V-belts have a tendency to wind around the motor pulleys, and being thus rapidly whirled about the motor shaft, cause.

considerable damage.

The present invention has a double aspect and comprises means to indicate when a belt is broken, or means to stop the particularmotor which ran the broken belt, on the one hand, and means to prevent a broken belt i from winding around the motor shaft, on the other hand. The use of the latter means is, in the illustrated embodiment of the invention, quite necessary to the successful operation of the former means, and they therefore constitute a single invention; nevertheless it is obvious that the apparatus employed to prevent the belt from winding about the motor shaft or pulley can'be employed singly andalso, with certain types of belt or chain, the detector or stop motion part of the invention could be used singly. j

In the best form of the invention known to me, the latter provides a detector element riding on the belt at one of the pulleys, and

when the belt breaksthe detector drops. 1 The; safety device to prevent the belt from wind? ing around the motor pulley maybe best PATENT OFFICE 1 understood from the following description.

v jIn the accompanying drawings, which show one form which the invention may take"?- Fig. 1 1s a side elevation of the apparatus ofthe-invention, shown in connection with an electric motor and pulley.

Fig. 2 is a plan view of the parts shown in Fig. 1. r

Fig. 3 is a vertical sectional view on an enlarged scale of a single'operatingidevice of the invention. 1

Fig. 4 is a front elevation of the parts shown in Fig. 1 but on'a larger scale. 7

5 is a'wiring diagram showing the use of an annunciator and alarm bell.

Fig; 6 is a wiring diagram showing the use of a circuit breaker.

Like reference characters refer tolike parts throughout the drawings.

The motor 1 which drives the fans of the macaroni drying machine is mounted on a table or stand of any desired type 2, and is preferably'locatedsubstantially on a level with the axes of said fans, instead of being mounted below them, as shown in the aforesaid patent to Sicignano. At all events, the motor 1 provides a motor shaft 3 which, as shown in Figs. 1 and 2, has a double pulley 4 fastened thereto. The pulley 4 provides a pair of grooves 5, 5, preferably of the general shape shown, and located in these grooves 5, 5, are the belts which drive the fans, the latter having driven pulleys, not shown, provided With grooves of form similar to the grooves 55, 5. The belts 6 which run in the grooves 5, 5 and drive the fans are best shown in Figs. 2 and 4 and comprise a plurality of laminated leather links suitably joined together. Since these belts by themselvesare not my invention, and since any other suitable type of belt or chain might be employed in connection with my invention, the belts will not be further described herein.

' The frame of the detector mechanism comprises a pair of U-shaped fiat steel members.

7 and 8. Between the legs of the member 8 extend a pair of horizontal rollers 9, 9 which provide trunnions 10, 10 that it in holes provided by the aforesaid legs of the member 8. The belts 6 are located above and below these rollers 9, 9; that is to say, the path of the belts 6 is as shown in Fig. 4, those portions of the belts that lead to or from the top of the pulley 4 being located above the top roller 9, and those portions of the belts that lead to or from the bottom of the pulley 4 passing below the bottom roller 9. These rollers 9, 9 act to take the force of a broken belt as it starts to whip and prevent the belt from smashing the motor, the device or other adjaeven if slack when stopped, due to centrifugal force, and this tension wedges them into the V grooves 5, 5 as they pass around the pulley 4; upon breakage of a belt, the tension which normally causes the belt to pull out of the groove is. released, and as the individual links are still wedged into the groove, they have a tendency to follow right around the pulley. To a certain extent, the rollers 9, 9 prevent this action, or at least they act to cause the broken belt to unwind from the pulley as it starts to whip, but the following device is also employed to .prevent the belts from ever winding about the pulley As best shown in Figs. 1 and 4, a shaft 11 eXtends between the legs of the member 8, passing through holes in the latter and being rigidly secured thereto by means of nuts 12, 12, 12, 12 on the threaded. ends of said shaft. The shaft 11 is located between the rollers 9, 9 and level with the axis of the motor shaft 3 (in cases where the motor is level with the axes of the fans). The shaft 11 serves to hold a member 13 which comprises a hub portion 14 with a hole therethrough,

and two pairs of fingers 15, 15 of the shape shown in Fig. 4. These fingers 15, 15 extend into the grooves 5, 5 just above and below the belts 6 and constitute guards to prevent the belts from ever winding completely around the pulley under any circumstances. The member 13 is held in place on the shaft 11 by means of a set screw 16 extending through the hub 14, and can therefore be adjusted longitudinally and axially of said shaft.

. The finger guards 15, 15 alone will probably in most cases prevent damage being done by a broken belt, but the rollers 9, 9 serve as additional safetydevices. If desired the lower roller 9 can be omitted, but it is desirable toemploy the upper one at least, as this prevents a sagging belt from coming in full contact with the upper finger 15 and breaking it. 'Referring now particularly to Figs. 1, 3 and 4, a cross-piece 17 extends betweenthe tops of the brackets or frame members 7 and 8 and is suitably fastened thereto. This cross piece 17 serves to hold a pair of bushings 18, 18 which extend therethrough, said bushin'gs being provided for the slidable reception of plungers 19, 19. As best shown inFig. 3, each plunger 19 comprises a tubular member 20'having a long slot 21 extending longitudinally thereof, the member 20 being plugged atthe upper end by a cylindrical member 22 and at the lower end by a forked member 23, which has an upwardly extending cy indri, cal portion. Pins 24 and 25 serve to hold these members together as a unit.

Extending through the bushings 18, 18 and through the slots 21 in 'thetubular members 20 are pins 26, 26, which thus serve to hold the plungers 19, 19 from rotatable movement while allowing them to move up and down. .Inside of each member 20 is a; spring 27 the lowerend of which presses against the top of one of the forked members23, and the upper end of .which reacts against one of the pins 26. These springs 27 thus assist gravity in holding the plungers 19 down and prevent it from moving upwardly too violently, as will be hereinafter explained.

The forked members 23 support rollers '28, 28 which are located above the respective grooves 5, 5. Preferably each roller provides a ball bearing 29, the outer race of which is pressed into a roller 28 and the inner race of which is pressed onto a pin 30 which extends between the prongs of each forked member 23. The rollers 28, 28, which are preferably made of some light material such as rubber, are thus mounted at the lower end of the plungers '19, 19 in anti-friction bearings, and rest against the belts 6, 6 when the device is in operation.

Suitably fastened to the top of the cross piece 17 is a piece of insulation 31, in the top of which is a metallic insert 32. Fastened to the top of the members 22, as by means ofscrews 33, are metallic contact members 34.

In the absence of a belt in a particular groove 5, the plunger 19, associated with and just above said groove, will assume a downward position, as illustrated in Fig. 3. Under such conditions, one of the contact members 34 is in engagement with the metallic insert 32,

which completes an electric circuit, to be described. But when both belts 6, 6 are around the pulley 4, as shown in Fig. 4, both plungers 19, 19 are raised and neither of the contact members 34 is in engagement with the metallic insert 32.

Referring now to the wiring diagram of Fig. 5,'in which the conventional electrical symbols have been used, the motor 1 is indi cated, and in case alternating single phase current is used, as indicated by the line 35. the motor may be shunt wound, as indicated at 36. At 37 is a reversing switch which is preferably operated by the clock mechanism referred to. At 38 is a double pole switch which controls the shunt winding and the armature winding. In the embodiment of the invention illustrated by Fig. 5, it is intended that the switch 38 be manually operated.

As indicated in the lower part of the wiring diagram of Fig. 5, the detector device of the invention is connected in circuit with a battery 39, an alarm bell 40, and a drop annunciator 41, the last two being preferably in parallel. This connection is made through suitable terminals 42 and 43, the former being a binding post located on the metallic insert 32 and the latter being any suitable ground connection. It will be at once evident that, when a belt breaks, one of the plungers 19 will drop, and the electric circuit will be completed through the bell 40 and annunciator 41 by contact of a member 34 with the insulated piece of metal 32. Thereupon the operator of the drying rooms will proceed to the switch 38 and stop the motor 1.

According to the wiring diagram of Fig. 6, the same alternating single phase line 35 is employed. In this case also a reversing switch 37 is utilized to reverse. for example, the shunt field 36 of the motor 1. In the line 35 is a suitable circuit breaker 44. which-is independently tripped by a coil 45 in circuit with the battery 39 and the terminals 42 and 43. The wiring diagram of Fig. 6 simply illustrates one wavof making my device operate automatically to stop the driving motor 1 when a belt breaks, as will be readily apparent. In showing two wiring diagrams for my invention. it should be understood that I am not limited thereto, as other electrical connections of the device may be made, and other types of motors may be used than that indicated.

It will be observed that the plunger units 19, 19 are of comparatively light construction and this is desirable in order to eliminate wear 27 are employed so that the plungers will notjump too high whenthe separate links in the belts 6 strike them and thus wear out the bushings 18, 18. The net result of both of these things is the same amount of pressure of the rollers 28 on the belts as though the springs were omitted and the plungers 19 made heavier, but the inertia of-the parts is less and they seem to last longer and wear better when made as indicated. The above is simply given by way of explanation for the construction shown, and is not to be taken as limiting the device thereto.

I claim, I,

1. In apparatus of the class described, a pair of grooved pulleys, a belt connecting and passing around said pulleys, said belt being made of leather links, and means to prevent said belt from whipping around said pulleys.

or either of them upon breakage of said belt, said means including a roller located between the courses of said belt and a finger located in the groove of the pulley between said roller pulley shaft when the belt breaks, thereby permitting said detector to operate.

3. In apparatus of the class described, a pulley, a groove in said pulley, a belt passing around said pulley and located in said groove, and a pair of fingers carried by a stationary element, said fingers being located in said groove close to said belt, to prevent said belt from Winding around said pulley upon breakage thereof.

4. In apparatus of the class described, a pulley, a groove in said pulley, a belt passing around said pulley and located in said groove, and a finger carried by a stationary element, said finger being located in said groove close to the outwardly moving course of said belt, to prevent said belt from winding around said pulley upon breakage thereof.

ALFRED ALEXANDER BIANCHI. A 

